A new study has found that older men and women in the South are more often prescribed antibiotics than older Americans elsewhere, even though there is no evidence that the South has higher rates of pneumonia and other diseases for which antibiotics are necessary. The findings suggest there are greater rates of antibiotic overuse in that part of the country.
Many experts have expressed concerns that antibiotics are being overprescribed and overused, leading to unnecessary spending on prescription medicines as well as more widespread bacterial resistance to the drugs. In the elderly, who are more likely to suffer adverse side effects and reactions from antibiotics, the health consequences can be amplified.
Despite this vulnerability, antibiotic use among seniors has not been as closely studied as it has been among younger Americans. So a team of researchers looked at prescribing patterns among men and women over 65 across the country, comparing rates over a period of several years and doing breakdowns quarterly. Their research, published in Archives of Internal Medicine, showed that during a typical three-month period, about 21.4 percent of older Americans in the South used an antibiotic, compared with about 17.4 percent in the West. The rate in the Midwest was 19.2 percent, and in the Northeast it was 18.2 percent.
The researchers adjusted their findings for health status, demographics, insurance coverage and other differences that could have influenced the findings. Even after controlling for these variables, the rate in the South remained higher. The study was not designed to determine specifically whether antibiotics in the South are overprescribed, but the data point to overuse as a likely explanation, said Dr. Yuting Zhang, an author of the study and assistant professor of health economics at the University of Pittsburgh.
"We don't know the exact reason," she said, "but what we can say is that antibiotic use is higher in the South, and this is consistent with previous research that shows the quality of prescribing is poorer in the South compared to other regions."
Dr. Zhang and her colleagues found that there were also seasonal variations in antibiotic use. Regardless of region, antibiotic prescription rates tended to peak in the first quarter of the year, from January through March, and then drop to a nadir during the third quarter, from July through September. The seasonal peak is probably related to the rise in respiratory infections during the winter months, Dr. Zhang said. But since many people are infected by cold and flu in the winter months and these viral infections are not susceptible to antibiotics, the seasonal trends may reflect further evidence of poor prescribing patterns.
The findings were based on Medicare data collected from the beginning of 2007 through the end of 2009. The data was based on about one million patients per year.
Though antibiotic overuse remains common in all areas, one lesson from the findings is that it may be worthwhile to target the South with programs aimed at reducing unnecessary antibiotic use, Dr. Zhang and her colleagues noted, using rates in low-prescribing areas like the West as a goal.
An accompanying editorial from public health experts went further, calling the persistence of antibiotic overprescribing "a failure to translate national public health priorities and evidence into local practice and policies."
"We need to find better ways to compel individuals and organizations to address the significance of the problem of antibiotic overuse," they wrote. "Strategies to achieve transformation at these levels may need to differ substantially from the current educational approaches that have been in use among patients and clinicians thus far."